This section describes the conventions to be used when using a common file for CFD applications. Consistent application of these conventions will assure that data will be accessible to a developing base of pre- and post- processing tools. For a picture representation of the following definitions see the figure representing the common file layout for .cfl files.
Zone nodes are subnodes of the root node. A zone node is accessed and the header read through the following Fortran code fragment:
CHARACTER*32 ZNAME INTEGER ZONE INTEGER STATUS, RSTATE, ZSTATE ! Note that the default sizes of IPARZ, FPARZ and CPARZ are used. INTEGER IPARZ(64) REAL FPARZ(64) CHARACTER*80 CPARZ(2) ! RSTATE is the state of the root node returned by CFOPEN ! All zone nodes under the root node are named 'ZONE nnn' ZONE = zone number (1, 2, 3, etc.) WRITE (ZNAME, '(''ZONE '', I3)') ZONE CALL CFSNOD (STATUS, RSTATE, ZNAME, ZSTATE) CALL CFRNOD (STATUS, ZSTATE, IPARZ, FPARZ, CPARZ)After executing the above code, you may access the data for the zone through the state variable ZSTATE.
Boundary nodes are subnodes of a zone node. A boundary node is accessed through the following Fortran construct:
CHARACTER*32 BNAME INTEGER BNDRY INTEGER STATUS, BSTATE, ZSTATE ! All boundary nodes for a given zone are stored under the zone ! node with a name of 'BNDRY n' where n is a number defined below. BNDRY = boundary (1=I1, 2=IMAX, 3=J1, 4=JMAX, 5=K1, 6=KMAX, 7=Chimera, >= 8=Unstructured) WRITE (BNAME, '(''BNDRY '', I3)') BNDRY CALL CFSNOD (STATUS, ZSTATE, BNAME, BSTATE)
Interior nodes are subnodes of a zone node (for 3-D unstructured grids only). An interior node is accessed through the following Fortran construct:
CHARACTER*32 INAME INTEGER STATUS, ISTATE, ZSTATE ! An interior node for a given zone is stored under the zone ! node with the name 'INTERIOR'. INAME = 'INTERIOR' CALL CFSNOD (STATUS, ZSTATE, INAME, ISTATE)
Note: All dimensional values stored in the common sections of the node headers must be in SI units. Data stored in the application-specific sections can be in any units the application desires.
For unstructured grids, IPAR(1), IPAR(2), and
IPAR(3) are not used.
For a file containing both structured and unstructured zones, these
parameters will have the correct values for the structured zones.
Parameter | Definition
| ||
---|---|---|---|
IPAR(1) | Maximum I in all zones | ||
IPAR(2) | Maximum J in all zones | ||
IPAR(3) | Maximum K in all zones | ||
IPAR(4) | Number of zones | ||
IPAR(5) | Maximum number of points in any one zone | ||
IPAR(6) | Symmetry flag: 0 = no symmetry assumed, 1 = x-y axi-symmetric, 2 = y-z axi-symmetric, 3 = x-z axi-symmetric | ||
IPAR(7) | Mxset | ||
IPAR(8) | Rotation system flag: 0 = none, 1 = rotating system, 2 = gravity system | ||
IPAR(9-39) | Reserved for future use | ||
IPAR(40-64) | Reserved for application-specific data
| ||
FPAR(1) | p_{0}, freestream stagnation pressure | ||
FPAR(2) | T_{0}, freestream stagnation temperature | ||
FPAR(3) | a_{0}, freestream stagnation speed of sound | ||
FPAR(4) | ρ_{0}, freestream stagnation density | ||
FPAR(5) | M, freestream Mach number | ||
FPAR(6) | p, freestream static pressure | ||
FPAR(7) | T, freestream static temperature | ||
FPAR(8) | a, freestream speed of sound | ||
FPAR(9) | ρ, freestream density | ||
FPAR(10) | k, freestream k of k-ε or k-ω turbulence models | ||
FPAR(11) | ε or ω, freestream ε or ω of k-ε or k-ω turbulence model | ||
FPAR(12) | μ, freestream viscosity | ||
FPAR(13) | Re, Reynolds number | ||
FPAR(14) | α, angle of attack | ||
FPAR(15) | β, yaw angle | ||
FPAR(16-23) | Reserved for future use | ||
FPAR(24) | β_{∞}, effective γ | ||
FPAR(25) | R, gas constant | ||
FPAR(26) | γ, ratio of specific heats (1.4) | ||
FPAR(27) | Pr, Prandtl number (0.72) | ||
FPAR(28) | Pr_{t}, turbulent Prandtl number (0.9) | ||
FPAR(29) | x, x base point of axi-symmetric line | ||
FPAR(30) | y, y base point of axi-symmetric line | ||
FPAR(31) | z, z base point of axi-symmetric line | ||
FPAR(32) | M, slope of axi-symmetric line | ||
FPAR(33) | A, angle of rotation about axi-symmetric line | ||
FPAR(34-36) | Rotation system xyz center (IPAR(8) = 1) | ||
FPAR(37-39) | Rotation system xyz rotation rate (IPAR(8) = 1), or gravity system xyz terms (IPAR(8) = 2) | ||
FPAR(40-64) | Reserved for application-specific data
| ||
CPAR(1) | Grid title | ||
CPAR(2) | Flowfield title |
Parameter | Definition
| ||
---|---|---|---|
IPAR(59) | Last time level completed (Global Newton) | ||
IPAR(60) | −1 for new format global header | ||
IPAR(61) | Last I plane completed (marching) | ||
IPAR(62) | Last zone completed | ||
IPAR(63) | Number of k-ε cycles | ||
IPAR(64) | Number of cycles
| ||
FPAR(60) | Global Newton big norm | ||
FPAR(61) | Global Newton L2 norm | ||
FPAR(62) | Global Newton max convergence variable ever |
Zone nodes can contain either structured or unstructured grids. These two types are distinguished based on IPAR(9) in the Zone Node Header. IPAR(9) will be 0 for structured grids and 1 or 2 for unstructured grids.
Parameter | Definition
| ||
---|---|---|---|
IPAR(1) | I dimension | ||
IPAR(2) | J dimension | ||
IPAR(3) | K dimension | ||
IPAR(4) | Number of fringe points | ||
IPAR(5) | Number of overlapping tracking definitions | ||
IPAR(6) | Size of overlapping definition work array | ||
IPAR(7) | Reserved for future use | ||
IPAR(8) | Rotation flag: 0 = Non-rotating; 1 = Rotating (see FPAR(11-16)) | ||
IPAR(9) | Grid type: 0 = Structured; 1,2 = Unstructured | ||
IPAR(10) | Gas model: 0 = Ideal gas 1 = Thermally perfect (frozen chemistry) 2 = Equilibrium air 3 = Finite rate | ||
IPAR(11) | Turbulence model: 0 = Euler (Inviscid) 1 = Laminar 2 = Baldwin-Lomax 3 = Cebeci-Smith 4 = k-ε (obsolete) 5 = Baldwin-Lomax and PDT 6 = Baldwin-Barth (1 equation) 7 = Spalart-Allmaras (1 equation) 8 = SST-Menter (2 equation, k-ω) 10 = Chien k-ε | ||
IPAR(12) | Cell/node/variable relationships 0 = Variable values are at node points 1 = Variable values are at cell centers | ||
IPAR(13) | Wall function mode 0 = No wall function 1 = White/Christoph model | ||
IPAR(20) | Boundary type for I = 1 boundary 0 = Undefined 1 = Reflection/symmetry 2 = Adiabatic wall 3 = Freestream 4 = Viscous wall 5 = Unused 6 = Unused 7 = Arbitrary inflow 8 = Outflow 9 = Inviscid wall 10 = Self-closing 11 = Singular axis 12 = Inviscid axis and wall (not used in Wind-US) 13 = Coupled/point by point 14 = Unused 15 = Bleed 16 = Pinwheel axis 17 = Frozen 18 = Chimera | ||
IPAR(21) | Boundary type for I = IMAX boundary | ||
IPAR(22) | Boundary type for J = 1 boundary | ||
IPAR(23) | Boundary type for J = JMAX boundary | ||
IPAR(24) | Boundary type for K = 1 boundary | ||
IPAR(25) | Boundary type for K = KMAX boundary | ||
IPAR(26) | Grid velocity flag; 0 = none, 1 = global, 13 = point by point | ||
IPAR(27-39) | Reserved for future use | ||
IPAR(40-64) | Reserved for application-specific data
| ||
FPAR(1-7) | Zone min/max (x_{min}, x_{max}, y_{min}, y_{max}, z_{min}, z_{max}, checksum) | ||
FPAR(8-10) | Global translation velocity (u, v, w) | ||
FPAR(11-13) | Global rotation velocity (v_{r}, v_{θ}, v_{ψ}) | ||
FPAR(14-16) | Global rotation center (x, y, z) | ||
FPAR(17-39) | Reserved for future use | ||
FPAR(40-64) | Reserved for application-specific data
| ||
CPAR(1) | Zone title | ||
CPAR(2) | Characters 1:40, grid generator identification | ||
Characters 41:80, flow solver identification |
Parameter | Definition
| ||
---|---|---|---|
IPAR(1) | Number of points | ||
IPAR(2) | Total number of edges, including internal as well as boundary edges. (Optional; only needed if edge data structure is stored.) | ||
IPAR(3) | Total number of faces, including internal as well as boundary faces. | ||
IPAR(4) | Number of cells (0 --> surface) | ||
IPAR(5) | Max number of nodes per face | ||
IPAR(6) | Max number of faces per cell | ||
IPAR(7) | Number of surface offset data entries | ||
IPAR(8) | Max number of nodes per cell | ||
IPAR(9) | Grid type: 0 = Structured 1 = Unstructured (tetrahedral) 2 = Hybrid (mixed element types) | ||
IPAR(10) | Gas model: 0 = Ideal gas 1 = Thermally perfect (frozen chemistry) 2 = Equilibrium air 3 = Finite rate | ||
IPAR(11) | Turbulence model: 0 = Euler (Inviscid) 1 = Laminar 2 = Baldwin-Lomax 3 = Cebeci-Smith 4 = k-ε 5 = Baldwin-Lomax and PDT | ||
IPAR(12) | Cell/node/variable relationships: 0 = Variable values are at node points 1 = Variable values are at cell centers | ||
IPAR(13) | Number of fringe points | ||
IPAR(14) | Number of sequenced cells | ||
IPAR(15-18) | Reserved for flow code use | ||
IPAR(19) | Total number of elements (CGNS) | ||
IPAR(20) | Number of boundary points | ||
IPAR(21) | Number of boundary edges | ||
IPAR(22) | Number of boundary faces | ||
IPAR(23) | Boundary condition type (also used to distinguish between 2-D and
3-D grids): 0 = Face (3D) 1 = Node (3D) 2 = Edge (2D) 3 = Node (2D) | ||
IPAR(24) | Number of closed boundaries (Curves-2D, Surfaces-3D) up to a maximum of 20 | ||
IPAR(25-58) | Array of boundary size pairs: (25,27,...) - No. of points (2D or 3D surface) (26,28,...) - No. of faces (Full 3D boundary) | ||
IPAR(60) | Number of overlapping tracking definitions | ||
IPAR(61) | Size of overlapping definition work array
| ||
FPAR(1-39) | Reserved for future use | ||
FPAR(40-64) | Reserved for application-specific data
| ||
CPAR(1) | Zone title | ||
CPAR(2) | Characters 1:40, grid generator identification Characters 41:80, flow solver identification |
Parameter | Definition
| ||
---|---|---|---|
IPAR(1) | BC format: 0 = old, 1 = new | ||
IPAR(8) | Unstructured offset (CGNS) | ||
IPAR(20) | BC code (CGNS) | ||
IPAR(40) | Wall function mode 0 = No wall function 1 = White/Christoph model | ||
IPAR(58) | Boundary rotation mode | ||
IPAR(59-64) | Rotation specific data depending on mode
| ||
FPAR(40) | Capture area (see zonal FPAR(64)) | ||
FPAR(41) | Bleed area (see BLAREA
variable)
| ||
CPAR(1) | Capture area region name | ||
CPAR(2) | Bleed area region name |
Parameter | Definition
| ||
---|---|---|---|
x | x, x coordinate | ||
y | y, y coordinate | ||
z | z, z coordinate | ||
IBLANK | Blanking data asscociated with overlapping grids | ||
ui | x direction grid velocity | ||
vi | y direction grid velocity | ||
wi | z direction grid velocity |
The variables x, y, and z are located under the zone node for structured grids. For unstructured grids, x, y, and z for the boundary points are located under the zone node and x, y, and z for the interior points (3D) are located under the interior node. Note that IBLANK has labels encoded in it as follows: 1 = a normal point, −(label + 1) = a hole point, and +(label + 1) = a fringe point, where label is a positive number.
The following variables are applicable to unstructured grids only, and
are located under the zone node for boundary surfaces and under the
interior node for volumes.
These variables describe the connectivity of the faces and/or edges.
Variable | Definition | ||
---|---|---|---|
facpi | Index for point i of a face, i = 1 to the number of points per face. facp4 = 0 for triangular faces in a mixed quad/tri face grid. The facp values for a particular face should be oriented such that the face normal points into the domain. | ||
edgpi | Index for point i of an edge segment | ||
facei | Index for edge i of a face, i = 1 to the number of edges per face |
The following variables are applicable to unstructured grids only, and
are located under the the interior node.
These variables describe the connectivity of the cells.
Variable | Definition | ||
---|---|---|---|
celpi | Index for point i of a cell, i = 1 to the number of points per cell. celpi = 0 for nodes of dimensionality greater than the current cell. (I.e., celp5 = 0 for a tetrahedral cell.) | ||
celfi | Index for face i of a cell, i = 1 to the number of faces per cell | ||
celtyp | The type of cell (see definition of IPAR(63) under "Wind-US Zonal Node Application Specific Data"). Used for hybrid unstructured grids only. |
The following variables are applicable to unstructured grids only, and
are located under the zone node.
These variables describe collections of faces or surfaces.
Currently, each surface must contain only a single face type (i.e., all
triangles or all quads).
Each of these variables are of size nsurfs = ipar(7).
Variable | Definition | ||
---|---|---|---|
srfoff | Starting index in the face list of a surface segment | ||
srfsiz | Number of faces on a surface segment | ||
srfid | ID number for a surface segment | ||
srfbc | Boundary condition for a surface segment, BC codes same as structured grid | ||
srfvrt | For hybrid grids, the number of points per face for all faces of that boundary surface | ||
srfpts | Number of points referenced by all of the faces on that boundary surface |
Variable | Definition | ||
---|---|---|---|
rho | ρ, density | ||
rho*u | ρu, x component of momentum per unit volume | ||
rho*v | ρv, y component of momentum per unit volume | ||
rho*w | ρw, z component of momentum per unit volume | ||
rho*e0 | ρe_{0}, stagnation energy per unit volume | ||
P | p, pressure | ||
T | T, temperature | ||
u | u, x component of velocity | ||
v | v, y component of velocity | ||
w | w, z component of velocity | ||
e0 | e_{0}, stagnation energy per unit mass | ||
M | M, Mach number | ||
s | s, entropy | ||
h | h, enthalpy | ||
omegax | Ω_{x}, x component of vorticity | ||
omegay | Ω_{y}, y component of vorticity | ||
omegaz | Ω_{z}, z component of vorticity |
Variable | Definition | ||
---|---|---|---|
mul | μ_{l}, laminar viscosity | ||
mut | μ_{t}, turbulent viscosity | ||
k | k, kinetic energy (k-ε model) | ||
rho*k | ρk (k-ε model) | ||
epsilon | ε, rate of dissipation (k-ε model) | ||
rho*epsi | ρε (k-ε model) | ||
K | k (k-ε and SST models) | ||
omega | ω (SST model) | ||
anut | ν_{t} (Baldwin-Barth and Spalart-Allmaras models) |
Variable | Definition | ||
---|---|---|---|
a | a, local speed of sound | ||
beta | β, effective gamma | ||
Z | Z, compressibility | ||
kappa | κ, thermal conductivity | ||
etake | ν_{K.E.}, kinetic energy efficiency | ||
PHI | Mass fraction of non-reacting species | ||
H | Mass fraction of H | ||
N | Mass fraction of N | ||
O | Mass fraction of O | ||
H2 | Mass fraction of H_{2} | ||
N2 | Mass fraction of N_{2} | ||
O2 | Mass fraction of O_{2} | ||
OH | Mass fraction of OH | ||
NO | Mass fraction of NO | ||
H2O | Mass fraction of H_{2}O | ||
CO2 | Mass fraction of CO_{2} | ||
rho*H | ρH, ρ times the mass fraction of H; similarly for N, O, etc. |
Variable | Definition | ||
---|---|---|---|
Cp | C_{p}, pressure coefficient | ||
delta* | δ^{*}, displacement thickness of boundary layer | ||
THETA | θ, momentum thickness of boundary layer | ||
Redelta* | Re_{δ*}, Reynolds number based on δ^{*} | ||
Cf1 | C_{f1}, skin friction in I direction | ||
Cf2 | C_{f2}, skin friction in J direction | ||
Cf3 | C_{f3}, skin friction in K direction |
The following variables are used by Wind-US.
For the new BC format, the "_n" variables are for node-centered
grids, and the "_c" variables are for cell-centered grids.
For cell vertex grids the size of the boundary is the number of points,
and for cell-centered grids it is the number of faces.
Variable | Description | Location | Type
| |||
---|---|---|---|---|---|---|
maxr | Max residual for all zones for each equation | Root | Real | |||
BLAREA | Bleed area | Root | Real | |||
SETDATA(3,*) | For each set; (1,*) = # iterations, (2,*) = max residual, and 3 = integrated time (located under zone node) | Zone | Real | |||
LABLST | Label for overlapping tracking | Zone | Integer | |||
LABTYP | Hole/fringe type for overlapping tracking | Zone | Integer | |||
LABIND | Index into LABDEF for overlapping tracking | Zone | Integer | |||
LABDEF | Generation data for overlapping tracking | Zone | Real | |||
NZN | If > 0, zone coupled to; if ≤ 0, boundary condition | Boundary | Integer | |||
NBD | Boundary coupled to | Boundary | Integer | |||
IFRG | The I value of the fringe point (FRNGBND) | Boundary | Integer | |||
JFRG | The J value of the fringe point (FRNGBND) | Boundary | Integer | |||
KFRG | The K value of the fringe point (FRNGBND) | Boundary | Integer | |||
I1 | Node coupled to (first coordinate) | Boundary | Integer | |||
I2 | Node coupled to (second coordinate) | Boundary | Integer | |||
I3 | Node coupled to (third coordinate) | Boundary | Integer | |||
F1 | First coordinate tri/bilinear interpolating factor | Boundary | Real | |||
F2 | Second coordinate tri/bilinear interpolating factor | Boundary | Real | |||
F3 | Third coordinate trilinear interpolating factor | Boundary | Real | |||
Zone_[nc] | If > 0, zone coupled to; if ≤ 0, boundary condition | Boundary | Integer | |||
BndryNo_[nc] | The number of the boundary coupled to | Boundary | Integer | |||
Cell_n,Cell_c | The cell number containing the coupled point/face. For structured grids it is the IJK product for the point. | Boundary | Integer | |||
CCell_n,CCell_c | The cell number in the coupled zone containing the coupled point/face. | Boundary | Integer | |||
CellLoc_n1,2,3 | For structured grids, the IJK location plus the bilinear factor in the coupled-to cell. For unstructured grids, the 1,2,3 weighting factor of the 1,2,3 boundary face point. For quads the fourth weighting factor is 1.0 − ∑(1,2,3). | Boundary | Double | |||
CellLoc_c1,2,3 | For structured grids, the IJK location plus the bilinear factor in the coupled-to cell. For unstructured grids, the X,Y,Z value of the cell center of the coupled face. | Boundary | Double | |||
CFace_c | Face used to parameterize XYZ in CellLoc_c | Boundary | Integer | |||
Trans | Turbulent transition specification array | Boundary | Real | |||
Temp | Temperature specification array, K | Boundary | Real |
For hybrid grids we have the following. When an unstructured cell-centered grid is coupled to a structured vertex-centered grid, the CellLoc_c data contains the structured bilinear factors used by the structured zone to interpolate the data to the unstructured face-centered location. For the other way, CellLoc_n contains the parameterized value of the structured point being coupled. The parameterization is based on the unstructured zone's face that is coupled to. This face number is stored in the CFace_n array. This is done since this face is not unique. Note this is not a problem for cell-centered unstructured-to-unstructured, since the parameterization is based on the unstructured face being coupled, and so there is no ambiguity. The follow code segments define the parameterization of the XYZ values into CellLoc_x.
The following takes the parameterization back to XYZ:
!----- Copy out the parameterization e123(1:3) = paramxyz(n,1:3) !----- Calculate the coordinate vectors if ( VrtcsPerBndryFace >= 4 .and. facep(4,n) > 0 ) then !----- Quad face v123(1,1:3) = VrtxXyz(facep(3,n),1:3) - VrtxXyz(facep(1,n),1:3) v123(2,1:3) = VrtxXyz(facep(4,n),1:3) - VrtxXyz(facep(2,n),1:3) else !----- Tri face v123(1,1:3) = VrtxXyz(facep(2,n),1:3) - VrtxXyz(facep(1,n),1:3) v123(2,1:3) = VrtxXyz(facep(3,n),1:3) - VrtxXyz(facep(1,n),1:3) end if norm(1) = (v123(1,2)*v123(2,3) - v123(2,2)*v123(1,3)) norm(2) = (v123(1,3)*v123(2,1) - v123(2,3)*v123(1,1)) norm(3) = (v123(1,1)*v123(2,2) - v123(2,1)*v123(1,2)) v123(3,:) = norm / sqrt(sum(norm**2)) * sqrt(sum(v123(1,:)**2)) !----- Calculate the xyz cell center xyz(n,1) = VrtxXyz(facep(1,n),1) + sum(e123*v123(:,1)) xyz(n,2) = VrtxXyz(facep(1,n),2) + sum(e123*v123(:,2)) xyz(n,3) = VrtxXyz(facep(1,n),3) + sum(e123*v123(:,3))
The following parameterizes XYZ based on the input face:
!----- Setup the equations if ( VrtcsPerBndryFace >= 4 .and. facep(4) > 0 ) then !----- Quad face v123(1,1:3) = VrtxXyz(1:3,facep(3)) - VrtxXyz(1:3,facep(1)) v123(2,1:3) = VrtxXyz(1:3,facep(4)) - VrtxXyz(1:3,facep(2)) else !----- Tri face v123(1,1:3) = VrtxXyz(1:3,facep(2)) - VrtxXyz(1:3,facep(1)) v123(2,1:3) = VrtxXyz(1:3,facep(3)) - VrtxXyz(1:3,facep(1)) end if norm(1) = (v123(1,2)*v123(2,3) - v123(2,2)*v123(1,3)) norm(2) = (v123(1,3)*v123(2,1) - v123(2,3)*v123(1,1)) norm(3) = (v123(1,1)*v123(2,2) - v123(2,1)*v123(1,2)) v123(3,:) = norm / sqrt(sum(norm**2)) * sqrt(sum(v123(1,:)**2)) b123 = xyzc - xyz(:,facep(1)) !----- Use Cramer's rule to solve the equations Ax = B call bg_ggutil_linsolve3x3_f ( status, v123, b123, e123 ) if (status /= 0 ) e123 = 0
Last updated 14 July 2005